Field of the Invention
The invention relates to the field of production of ion exchange resins and complexing sorbents and can be used, in particular, to extract ions of scandium from acidic process solutions.
Description of Related Art
At the present time, liquid and solid extractants, as well as ion exchange resins, are used for extraction of scandium from solutions. Notably, both extractants and ion exchange resins have inherent advantages and drawbacks.
For the purpose of combining the advantages of solvent extraction and ion exchange, porous carriers impregnated with selective extractants have been proposed. For example, equilibrium and kinetic characteristics of sorption materials based on tributyl phosphate, di-isooctyl methylphosphonate, and phosphine oxide, which are recommended for the extraction of scandium from acidic solutions, were studied (V. Yu. Korovin et al. “Sorption materials for extraction of scandium from acidic environments”, Problems of Chemistry and Chemical Technology, 2008, No. 2, p. 158).
A method is known to produce chelate sorbent, represented by polystyrene-azo-3-arseno-phenol, which is recommended for selective extraction of scandium from solutions with subsequent analytical determination (RU 2010876, 15 Apr. 1994).
A method is known to produce an ion exchanger for extraction of scandium by copolymerization of nitrile, acrylic acid, divinylbenzene and 5-vinyl-α-picoline with subsequent phosphorylation of the oxidized matrix by phosphorus trichloride (SU 1835403, 23 Aug. 1993).
A method is known to produce an ion-exchange resin for scandium extraction that provides copolymerization of vinylidene phosphoric acid with styrene, acrylic acid and divinylbenzene (U.S. Pat. No. 5,449,462, 12 Sep. 1995).
A method is known to produce a complex-forming ion exchanger for extraction of scandium, involving phosphorylation with phosphorus pentachloride of a styrene-divinylbenzene copolymer chloromethylated and aminated with diethanolamine or dimethylethanolamine (RU 2010804, 15 Apr. 1994).
In general, the known materials have a low selectivity to scandium, especially in case of presence of iron (III) in the solution, which results in increased costs for extraction of scandium and a more expensive scandium end product.
A method is known to produce a sorbent selective for scandium which includes acylation of macroreticular styrene-divinylbenzene copolymer in the presence of a Friedel-Crafts catalyst (aluminum chloride) at room temperature for 80 hours, phosphorylation of the acylated copolymer with phosphorus trichloride (M. Marhol, H. Beranova, K. Cheng <<Selective ion-exchangers containing phosphorus in their functional groups>>, Journal of Radioanalytical Chemistry, 1974, Volume 21, Issue 1, pp 177-186.).
In a known method, the acylation step is carried out using carbon disulfide as solvent, resulting in fire and explosion hazard of the process. A known method is characterized by high duration of the acylation step, resulting in generally poor production effectiveness of the process. Furthermore, the selectivity of the sorbent for scandium is insufficient.
A method is known to produce a sorbent that can be used to extract scandium from solutions and includes the step of acylating a styrene-divinylbenzene copolymer with acetyl chloride in dichloroethane solution in the presence of anhydrous aluminum chloride, washing, drying, the step of phosphorylation of the acylation product with phosphorus trichloride, the step of hydrolysis with ice water, washing, drying, oxidation of the dried product with 25% nitric acid, and final rinsing of the target product (RU 280839, 20 Nov. 1970).
The drawback of this method is low selectivity of the sorbent for scandium.